The aluminum alloy extrusion process involves forcing the aluminum alloy through the die. Because demand has been increasing for many years, it is useful for product design and manufacturing. Products made by this process have many applications. The industries benefiting include automobile, aerospace, electronics and construction. The following is a process guide for the steps and types of finishes that can be achieved.
What is the aluminum alloy extrusion process?
Preparation of extrusion die
First, we use H13 steel to process round moulds. Or, if we have a mold that fits your specifications, we can use it. This can even save the preparation time required to make one. Then, before extruding, we preheat the mold to about 450 to 500 degrees. This will help extend the service life of the mold and ensure a uniform flow of metal. After preheating, we load the extruder to start.
Extrusion CNC processing:
Preheating of aluminum billet
The billet is a cylindrical solid aluminum alloy block. We cut it from a long section of alloy log. We preheat it to 400 to 500 degrees Celsius in the oven. This gives it sufficient ductility for extrusion. However, we did not reach the melting state to protect the equipment.
Extrusion transfer to blank
We mechanically transfer the preheated blanks to the extruder. This is after the use of release agents or lubricants. It prevents the plunger from sticking to the blank.
Pressing to push the blank into the container
Once loaded into the press, the hydraulic cylinders push the malleable billets. It does this by applying pressure of up to 15000 tons. This forces the material to expand and fit into the vessel wall.
The appearance of material extruded by die
When the container is filled, the material is pressed against the extrusion die. Continuous pressure forces the aluminum material through the mold opening. This is because it has no other escape route. Therefore, it will appear after fully forming the opening shape of the mold.
Guide extrusion together with quenching jump table
Aluminum alloy extrusion
Once the aluminum extrusion comes out of the mold, a puller will grasp it and guide it along the runout table. However, the speed must match the exit speed of the press. The ratio depends on the profile difficulty, wall thickness, part weight and aluminum alloy selection. When the extrusion moves along the worktable, we use a water bath or a fan to uniformly quench it.
Shear the extrusion at the table length
We cut the extrusion after reaching the entire table length. The hot saw does this to separate it from the extrusion process. However, even after quenching, the extrusion is not cool enough for further processing. This requires an additional step.
Cool extrusion at room temperature
We transfer the cutting part to the cooling table. Here, the profile is cooled to room temperature. This will allow the extrusion to be stretched later.
Move and Stretch Stretch Alignment
The extrusion process sometimes causes the profile to twist naturally. This must be corrected because it may affect the functionality of the product. We use stretchers to complete the task. We mechanically grasp the ends of the profile and pull it until it is completely straight. We do this in order to meet the specifications.
Move profile to complete sawing length
This is the last step after realizing straight bench length extrusion. At Wemmitt, we saw a predetermined length. It is usually between 7 and 22 feet long. The extrusions at this stage are matched with T4 tempering. However, we can age them in the oven to reach the temperature of T5 or T6.
Surface treatment of extruded aluminum products
This occurs after the extrusion is completed. We use it to enhance the properties of extrusion materials. The yield stress and tensile strength belong to these profiles. The oven accelerates the aging process to make the aluminum material reach T5 or T6 state.
This step is mainly to enhance the appearance and corrosion resistance of aluminum. Anodizing and other finishes will thicken the oxide layer of metal. It makes the metal more wear-resistant, improves the surface emissivity, and provides a porous surface, which is easier to accept dyes.